Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, a generator, a gearbox, a nacelle, and one or more rotor blades. The rotor blades are the primary elements for converting wind energy into electrical energy. The blades have the cross-sectional profile of an airfoil such that, during operation, air flows over the blade producing a pressure difference between the sides. Consequently, a lift force, which is directed from a pressure side towards a suction side, acts on the blade. The lift force generates torque on the main rotor shaft, which is geared to the generator for producing electricity.
The rotor blades typically consist of a suction side shell and a pressure side shell that are bonded together at bond lines along the leading and trailing edges of the blade. An internal shear web extends between the pressure and suction side shell members and is bonded to spar caps affixed to the inner faces of the shell members. With typical blade configurations, the shear web is a continuous member that spans between the spar caps. More specifically, as shown in FIG. 4, an interface 15 of a shear web 30 and a spar cap 34 of conventional construction is illustrated. As shown, the shear web 30 is typically constructed of a core material 28 laminated together with a rigid flange 27 to achieve a desired bond width for bond paste 29 applied between the spar caps 32, 24 and transverse ends 36, 38 of the shear web 30. This configuration, however, places significant stresses at the juncture 15 between the shear web 30 and spar cap 32, 34 and often results in the use of excess bond paste 29 to achieve a desired bond width at this critical juncture 15. The excess paste contributes unnecessary weight to the blade and can break off, thereby resulting in blade “rattling” during operation of the wind turbine (a common complaint from wind turbine owners and/or operators). Also, air voids and unpredictable squeeze-out of the bond paste in the typical configurations can result in areas of decreased bond strength, which is particularly problematic in sections of the blade where repair is not possible from within the rotor blade. In addition, conventional bond paste can be expensive.
Accordingly, the industry would benefit from an improved bonding configuration between composite components of the rotor blade that addresses one or more of the aforementioned deficiencies.